<!doctype html>
<html>
    <head>
        <style>
            #box{
                width: 252px;
                font: 25px/25px 宋体;
                background: #000;
                color: #9f9;
                border: #999 20px ridge;
                text-shadow: 2px 3px 1px #0f0;
            }
        </style>
    </head>
    <body>
        <div id="box">
        </div>
    </body>
</html>
<script>
    var map=eval("["+Array(23).join("0x801,")+"0xfff]");
    var tatris=[
        [0x6600],
        [0x2222,0xf00],
        [0xc600,0x2640],
        [0x6c00,0x4620],
        [0x4460,0x2e0,0x6220,0x740],
        [0x2260,0xe20,0x6440,0x4700],
        [0x2620,0x720,0x2320,0x2700]
    ];
    var keycom={
        "38":"rotate(1)",
        "40":"down()",
        "37":"move(2,1)",
        "39":"move(0.5,-1)"
    };
    var dia;
    var pos;
    var bak;
    var run;

    function start(){
        dia=tatris[~~(Math.random()*7)];
        bak=pos={fk:[],y:0,x:4,s:~~(Math.random()*4)};
        rotate(0);
    }
    function over(){
        document.onkeydown=null;
        clearInterval(run);
        alert("GAME OVER");
    }
    function update(t){
        bak={fk:pos.fk.slice(0),y:pos.y,x:pos.x,s:pos.s};
        if(t) return;
        for(var i=0,a2="";i<22;i++)
            a2+=map[i].toString(2).slice(1,-1)+"<br/>";
        for(var i=0,n;i<4;i++)
            if(/([^0]+)/.test(bak.fk[i].toString(2).replace(/1/g,"\u25a1")))
                a2=a2.substr(0,n=(bak.y+i+1)*15-RegExp.$_.length-4)+RegExp.$1+a2.slice(n+RegExp.$1.length);
        document.getElementById("box").innerHTML=a2.replace(/1/g,"\u25a0").replace(/0/g,"\u3000");
    }
    function is(){
        for(var i=0;i<4;i++)
            if((pos.fk[i]&map[pos.y+i])!=0) return pos=bak;
    }
    function rotate(r){
        var f=dia[pos.s=(pos.s+r)%dia.length];
        for(var i=0;i<4;i++)
            pos.fk[i]=(f>>(12-i*4)&15)<<pos.x;
        update(is());
    }
    function down(){
        ++pos.y;
        if(is()){
            for(var i=0;i<4&&pos.y+i<22;i++)
                if((map[pos.y+i]|=pos.fk[i])==0xfff)
                    map.splice(pos.y+i,1),map.unshift(0x801);
            if(map[i]!=0x801) return over();
            start();
        }
        update();
    }
    function move(t,k){
        pos.x+=k;
        for(var i=0;i<4;i++)
            pos.fk[i]*=t;
        update(is());
    }
    document.onkeydown=function(e){
        eval(keycom[(e?e:event).keyCode]);
    };
    start();
    run=setInterval("down()",400);
</script>
